Internal expanding brake



V- 1933 J. 5. REYNOLDS 1,934,769

INTERNAL EXPANDING BRAKE Filed Oct. 27, 1928 4 Sheets-Sheet l I N V ENTOR.

A TTORNEY.

1933. J. 5. REYNOLDS 1,934,759

INTERNAL EXPANDING BRAKE Filed Oct. 27, 1928 4 Sheets-Sheet 2 A TTORN EY.

Nov. 14, 1933. J. s. REYNOLDS INTERNAL EXPANDING BRAKE 4 Sheets-Sheet 3Filed Oct. 27, 1928 INVENTOR. c/i/ ff/W040;

A TTORNE Y.

1933. .1. s. REYNOLDS 1,934,769

INTERNAL EXPANDING BRAKE Filed Oct. 27, 1928 4 Sheets-Sheet 4 25 A6-250/ z 31 2 4? 36 E v 3 A TTORNE Y.

Patented Nov. 14, 1933 r s 1 11,934,759 A V INTERNAL xPA niNG- BRAKE JoyS. Reynolds, Detroit, Mich. Application October 27, 1928.1 Serial No.315,396 I 14 Claims. (01; 188-78) This invention relates to expandingmecha nism for internal brakes for automobiles. In .the.

usual automobile brake the road wheelis provided with a drum within theinterior of which is an lexpandible band usually contracted-by a springout of frictional contact with the corresponding face of the drum andcaused to be expanded to frictional engagement therewith by an expand Iing element usually a cam operated by a lever- .lQi which in turn isconnected by means ofja pull rod or cable with the brake operatinglever-of .the vehicle.

" The principal object of this invention is to pro-f vide an expandingmechanism including a cam i'iihaving a spiral face by means of which acon stant leverage is providedto cause expansion of the band and when"released to pressure by the contracting spring readily returns to'n0n-ex-. 26 panding position.

provision of a pair of rotatable members connected with the adjacentends of a split bandione of which is of cam like form whereby onrotation with the drum.

A further feature of the invention is in the provision of such'membersrotatable on an axis at a right angle to the axis of rotation of thedrum,-

to the cam member of which is connected a pulley and cable passingoutwardly from the interior of the drum to connection with the brakeoperating lever,

' These and other objectsand'novel features of the invention arehereinafter more fully described and claimed, and the preferred form ofconstruction of'an internal brake "expanding"mechanism embodying myinvention is shown in the accord-- panying drawings in which A V Fig. lis an elevation partly in section of the interior of a brake showing myimprov xp er as applied to the band. I p Fig. 2 is a section taken online 2-2 of Fig. 1. Fig. 3 is a plan view of the expander on a eniargedscale. 1

Fig. 4 is a section taken on line k iof Fig. 3 f j Fig. 5 is a sectionon an enlarged scale, taken.

on line 5-5 of Fig. 2.-

Fig. 6 is a section taken on line 6 4i. ofFig. 5

5 Fig,' 8 is a similar view showing the cablecons A further object ofthe invention resides in the;

thereof the band is expanded to frictional contact neciion and pp rttherefor at the point in which i itpassesinto the interior of the drum.7 I 7 Fig.9 is aidetail in perspective showing an end of the band towhich the expander is attached.

' Fig. 10 is a perspective View of the bracket providing a-support atone end'for the cam or wheel shaft. r

' Fig. 11 is a'detail in section showing the manner of attachment of thecable to the cam and operating pulley; v

Fig. l2 is a plan view .of the contracting spring illustrating themannerof assembly on the supports'therefor. e H

. The drum 1 is fixedly attached to. theautomo bile-wheel, the hub ofwhich is shown at 2 in Fig. 2. This hub hasa flange 3 and bolts 4 arepassed through apertures provided 'in' theflange and 7 through the buttend of the spokes 5 and the side wall of the drum 1, thus-securing theparts together. This wheel is understood to be mounted on the wheelspindle "6 by interposed bearings (not here shown). The'front wheel,as'is illustrated in Fig. 2; has the spindle pivotally mounted on theend of-the axle Tall of which is the usual construction. The drum isalso provided with the usual flange 8 and the brake band, hereillustrated as being of two parts 9 and 10, lies within this drum." Theouter face'of the bands has the usual brake lining-11 which may bebrought to frictional engagement with the drum.

it be formed o'fone or more parts as my, improved expander may beutilized with any of the well known forms of expanding bands; The drumis provided with a cover plate indicated at 12 and" r "this plate isformed with an aperture atits upper side in which the bracket 13 ismounted and secured tothe cover; plate by bolts 14. i This bracket 13hasan inwardly extending'portion or arm 15, the purpose "of whichishereinafter describedi "I'his bracket 13 is'also provided with a lug16 having anaperture and counterbored and threaded at its outer end toreceive the apertured and.

recessed nut 1'7 as shown in Figs. 3 and 8. The cable 18, by meansofwhichthe'expander is operated, extendsthroug'h the aperture PTO-ivided in the lug 16 and has a coiled spring '19 secured in the recess ofthe 'nut 1'7 at oneendand' at a distance therefrom issecured to'thecable as' at 20,.thepurpose of the spring being to prevent.

kinking or a sharp bend in the cable in the brake application and totakeup slack in thecable'. I 0

The band ends, as shown-clearly in Fig. 5, have the ends punchedinwardly as indicated at 21 and 22 providing tongues 23 and 24 whichhave beveled end portions engaging the correspondingly sloping faces ofthe member 25a pivotally secured to the arm 15 of the bracket13- Thefunction of this'member 25 is to insure that the band ends are held outof contact withthe drum when the band iscontracted as is hereinaftermore fully described. 1 a

The expander is shown more clearlyin Figs. 1

' to 5 inclusive and consists oi a cam member 25,

an operating pulley 26 therefor on a shaft 27, and a guide wheel 28 onthe shaft 29. These shafts 27 and 29 are threaded at their upper endsfor threaded relation with a threadedaperture provided therefor in therespective portions 21and 22 of the band ends'and at their lower endsareprovided with anenlarged threaded portion 30 and 31 respectively forthreaded relation with. a threaded aperture in the ends of therespective brackets 32 and 33. These bracketsare, in the.

assembled relation shown in Fig. 5, .formed with thehorizontal portionswhich havethe threaded aperture for the shafts 27 and 29 as abovedescribed and end portions extending upwardly at band and the cam wheel25, the cable pulley 26' and shaft 27' and-bracket therefor or whollysupported by the adjacent opposite end of the shaft andthus, with theselugs 45 turned. 180" band. Each of the shafts .27 and 29 are formed witha hexagonal head 40 having a terminal cylindrical portion 41' formedwith a circumferential groove 42 'for the end 43 of the contractingspring 44. This spring is formed with the end eyes 43 to engage in the,grooves 42 of each of the extensions'41 and tends to contract the bandends andthereby release the brake and in so doing the pivotal member25having the sloping faces for the'tongues 23 and 24 of theuband endscauses the same to withdraw from contact with the drum under the actionof the spring 44.

v For ease in .assemblythese brackets 32 and 33 are not fastened to therespective ends of the band but are merely slipped in place as abovedescribed and the shafts 2'7 and 29 assembled in position in. theapertures of the bracket and band which holdsthe' brackets 32 and 33 inparallelism with the portions 217and 22 of'the'band ends and betweenwhich the cam'and pulley and guide wheel are respectively positioned.

' Inasmuch as the spring 44 has considerable ten-* sion and wouldordinarily bedifficult to place in Fig. l2'to the position shown indotted lines, they are a considerably lessdistance apart. These endportions or eyesi43 of the; spring may-then be readily slippedthereoverand the bolts turned to position the eccentric lugs 45. Thisplaces the spring under tension. and then the eyes may be moved upwardlyon the members 45 to engagement in the groove formed in the cylindricalportions 41 of the extensions of the shaftends. Thisarrang'ement.permits the spring to'be asspeed of action of the parts.

sembled by the fingers and without use of tools except possibly to turnthe shafts to their final position as is shown more particularly inFigs.-

and not only provides a seat for the wheel when the band is contractedbut also upon turning the cam causes a quick lift to take up the slackof the band. This cam member 25 is secured by means of screws as shownto the cable pulley 26 therebelow.

gThe cable, as before stated, passes into the drum through the bracket13 and extends around the peripheral groove of the pulley 26 and has aterminalendportion 46 which is passed into an aperture provided thereforin the pulley and up wardly' into a conical split bushing-4? secured inanaperture in the cam wh el and cover plate therefor.- This end 46 maybe secured in the conical bushing by means of a solder 48 as shown inFig; 11. I V I The split bushing 47 is formed ofv two half parts and theaperture in the cam member'25 is greater in diameter than the transverseaperture 60 in the pulley which is in registration therewith. Thus, thebushing when-the parts are assembled 'as shown in Fig. 11, seats-on thepulley enabling pressure to be applied to the cable. The constructionalso permits the parts to be readily assembled by pushing the cablethrough the aperture 60 and the aperture in the cam 25 and the bushingplaced about the cable and inserted in thefaperturev therefor in the camthusproviding a secure fastening for the cable.

. higher part of the cam member toroll on .the wheel 28.1 This-rotationspreads the ends of the bands and causes a'frictional contact of theband with the drum and it is to be noted that at about.

the point a to the point b the periphery of the cam ison a radius fromthe axis of the shaft 27 and this determines the greatest possibleexpansion of the brake.

In practice the parts are so assembled and related that only aboutone-half'to threefourths of the rise of the cam is required'to set thebrake and the-reason for thisis that this spiral face (which'isreally aform of wedge) is relied upon to cause reverse rotation of the camthrough pressure exerted between the wheel 28 and cam by the contractingspring upon release or the pressure on the cable. I

It is also to be noted that tLe shafts 2'7 and 29 for the cam and wheelare at a ri ht angle to the axis of rotation of the drum and thus I amenabled to provide a cam with a slower lift than previous types of camexpander which are turned on an axis parallel with the axis of rotationof the drum and without sacrificing anything in the Upon release ofpressure on the cable and due'to the pressure of the spring 44, the cam25 and wheel 23 rotate in the reverse direction until the parts assumethe relationship shown inFig. 6 with the wheel face engaging the arcuateportion 2-3 9 of the cam which'forms' a seat for the wheel from which it59 in a dependingend of the plate60 to which.

This:

the point of contact. The expandedrelationship of the cam'and camwheel'is'shown in Fig. lwith approximately the highest pointof. thefcamin wheel 28 and the camface 29, causes a reverse rotation thereof untilthe wheel is seated in thearcuate-portion 25b of the cam and alsoas'thecontact with the wheel.

I provide a cover plate 49 for the carn'which is,

secured thereto and to the pulley 26 by. means of the screws ,50heretofore mentioned; This cover plate overliesthe facexof the cam asshown in Fig. 5 providing a flange'that rides in the circumferentialgroove 51* formed in the wheel 28;

This relationship of thefledgeiof the-cover plate 49 and groove 51holds'the-wheeland cam in their necessary alignment and r'naintains the.v

. through application'of a constant leverage in cam face inconta'ct'withthe face of the wheel.-

The band is here shown as being formed of the'twoparts 9 and 10 themechanism..for the expansion of which is hereinbefore described. Theopposite ends of these bands'have offset terminal portions 52 and53-which engage a re' tainerl element or lever indicated generally at54. This retainer .is pivotally supported at 55' in aisocket 56 carriedby thebracket 57 provided on thepart 58 of the spindle indicated bydotted lines in Fig. 1. This bracket is therefore stationarilypositioned relativeto thespindle and permits the lever'to turnonjengagement of the bandwith the brake drum and band.

' Theupper end'of'the lever'fiis' socketed at the brake'drum cover plate12 is attachedplate 60, as shown in Fig. 2, is rotatably mounted uponthe portion filof the spindle provided therefor andthe arrangement issuch that'rotative movement of the cover member l2 and plate 60causesmovement of the lever 54 in its pivotal mounting 55 and in thisconstruction shown the purpose is to cause pressure to be applied tothe. end .52. for instance, of the half band 9 'in the same directionas" it is applied to the end 21.0f thehalf band 10'in the directionin'which the 'xdrurn rotates as indicated by the arrow in Fig. 1." Thisdescription of the brake band and its operation is merely 'toimake Iclear the construction illustrated butsuch specific construction of aband and halves and the related parts 54,55; 58 andf60 are'not essentialto this invention which is directed to the "expanding element and methodof applying power to the expander to cause an expansion orcontraction ofthe band relative to the drumas it is to be understood that thisexpander is adapted ,for use with various types of construction of aninternal expanding band and at the split point thereof.'-

The function ofithe to frictional contact'therewith'that is,ro tation ofthe brake drum inthe direction of the arrow shown in Fig. 1 uponapplication ofgthe brake will cause the end2l to'tend to travelwith'thedrum thus relieving the pressure .on the cones spondingside ofthe pivotedmemberq25a and,

as the opposite end 22 of the band attempts to beveled ends of thetongues andthe respective ends of the band.

'From the described construction and arrangement particularly of theexpanding mechanism 7 it will be evident that by a'direct pull. upon thecable 18-the pulley 26 and cam 25 are rotated pivoted member 25a. is. topermit the same to follow the band endwhich 'tends to travel with thedrum upon being brought in a directionto increase thedistance betweenthecentersof rotation of thecam 25=andfguide wheel 28' and thus causesan expansion ofthe band at the split end or between separatepore tionsthereof; that upon release of the cable the spring44, by reason of thepressure between the a cam 25,and wheel 28' are rotatable on an axis ataright :angle to the axis of. rotation of the drum (which is thepreferred arrangement), a

cam and wheel of considerable diameter may be utilized'which enables thecam to be formed with a true spiral face for the reasons heretoforegiven and resulting in case of operationof the brake causing anexpansion thereof.

' One of the. results of the use of a cam of spiral form is that aconsiderable travel of'the cable is required to operate the expandertoset the ,brakeland with the higher leverage located at to carry thecablein a conduit'of the Bowden wire principle as has commonly been theease as any variations in the position of the cable cannot materiallyafiect the operation of the-ere pander. I

It is further to be observed that the device is comparatively simple andinexpensive construction, and that. the various objects of theinvention. are attained bythe construction de-- scribed. It is to beunderstood, however, 'thatthe invention contemplates the use of a camand a 'wheelsosconnected'with theadjacent ends of thebandas to causeexpansion :of the band by rotation of the cam in one direction anda'con-' traction thereof by pressure exerted on the partsas by'a spring;and that various departures fromthe specific details of the parts andtheir arrangement may be made withoutdeparting from the spirit-of thisinvention as set forth in.-the apepended claims.

Having thus fully described invention, what I claim and desire to secureby Letters Patent"v of the United States is p l. The combination witha'brake split brake band therefor of the expanding type,

drum and a:

of an expandingrnechanism' for thessaid bands comprising a rotatable camattached toone end",

of the band, a rotatable Wheel attached to the;

adjacent oppositejend of the band in face contact with the cam; thetcamand wheel being mounted to turn on parallel axes at practically I J aright angle tothe drum axis rotation of the cam in" one directioncausing an expansion of the band to frictional engagement with. thedrum, av cable-and pulley therefor: by means of which the cam may-berotated in a direction'to cause an expansion of the band, and-a springCausing! pressure contact of the wheel and cam to cause reverse rotationof the cam upon release of the;

cable. 1 1. 2. The combination with abrake drum and abrake band thereforof the expanding typej. of

an expanding mechanism for the said band com- 1 prising 'a rotatable cammember, a rotatable Wheel face {engagement therewith, the camand Wheelbeing rotatable on parallel axestat a right angle to'the axis ofrotation of the drum,

means for-rotating the cam member in a directionto cause an increaseindistance between the axes of 'rotationof the wheel and cam, and V aspring. causing pressure contact of the wheel 7 and cam whereby-areverse rotation of the cam is caused upon release of the operatingmeans;

and thereby contracting the band. a 3. The combination with'a brake drumand a brake band therefor having separable ends, of

an expander for the said band consisting of a cam member rotatablysupported by one end of the band, a Wheel rotatablysupported at theadjacent opposite end of the band and engaging the cam face said wheeland cam beingturnable on parallel axes at an angle to the drum axis,

means for rotating the cam in a direction "to increase thedistance'between the centers of rotation of the cam and wheel, and aspring tending to decrease the distance between said centers ofrotation.

'4. The combination with a brake drum and brake band therefor of thesplit expanding type, of an expanding mechanism for the band comprisinga cam,a shaft fixed at one end to one the cam, and means for rotatingthe cam to' spread the shaft centers.

5. The combination with a brake drum and brake band therefor havingspindle ends, of an expanding mechanism for the. band comprising arotatable cam member mounted, on one end ,of the'band, a'rotatable wheelin face'contact;

therewith mounted on the adjacent end of the band, the cam and wheelbeing rotatable on parallel axes at'a right angle tothe axis of rotation of the drum, means for rotating the 08.111111]. a direction toincrease the distance between the axes of rotation of the cam and wheel,and'aspring cau'singareverse rotation of the cam upon release of theoperating means therefor.

6. The combination with a rotatable brake drum and a brake band thereforof the split expanding type providing oppositely disposed end 7portions, of an expanding; mechanism for the band comprising a rotatablecam member sup ported atonerend of the band, said camhaving a face ofspiral form, a rotatable Wheel supported by the other end of thebandlying in face tically a right angle'to the axis of the drum, meansfor causing rotation of the cam to in-..

engagement with the cam, said wheeland cam being-'turnable upon parallelaxes, lying at praccrease the distance between'the axis ofrotation ofthe cam and wheel, and a spring exerting pressure between the cam andwheel causing reverse rotation of the cam upon release of the operatingmeans. I '7. The combination brake band therefor having separable ends,of

an expanding device comprising a rotatable cam carriedby one of thesaidends having a spiral face, a rotatablewheel lying in face engagementwith the cam and attached tothe other of said ends, said cam face at itslow point being formed with an arcuate recess having substantiallythesame radius as the wheel and providing a seat therefor when the camis turned to permiticontraction of the band whereby upon the beginningof rotation of the earn, a quick initial separation of the axes of thewheel and cam is provided, and a spring yieldably holding the cam andwheel faces in contact.

with a brake drum and a 8. The combination with a brake drum,1of a brakeband therefor having separable ends, of

an expanding device comprising a rotatable cam carried by one of thesaid ends having aface formed with an arcuate portion from one end ofwhich the rise of the cam starts, a rotatable wheel in face engagementwith the cam normally seat: ing in the arcuate recess of the" cam whenthe band is in contracted position, the cam and wheel being so mountedrelative to the respective-separable endsthat rotation of the cam in onedirection causes an expansionof the band to frictional engagementwiththe drum, means for rotating the cam,- and a spring holding the face ,ofthe wheel in pressure engagement with the face of the cam and tending torotate the, cam in the *reverse direction upon: release of: theoperating means. r 1

V9. The combination with a rotatable brake drum and a brake bandtherefor having separable ends, of an expanding'mechanism thereforcomprising a rotatable cam member connected to one end of the band, arotatable wheel in face engage- Q ment therewith connected with theother end of,

the band, said cam member being provided with a circular flangeportion'and thewheel being formed witha groove in which the periphery ofthe flange liesthereby maintaining the. wheel and cam in faceengagement, means for rotating the cam member to cause an increase indistance apart of the axes of rotation of the "cam and wheeL'anda'spring exerting pressure between the cam and wheel tending to causereverse rotation thereof.

'10.:The combination with a brake drum and a band thereforof the splitexpanding type, of a rotatable cam member attached to one end of theband and a rotatable wheel attached to the opposite adjacent end of theband, a shaft for the said cam,;a shaft for the wheel, the axes of whichare at a, right angle to the axis of rotation of the drum, said shaftsbeing attached at their upper ends to the respective ends of the band, abracket for the lower. ends of each of the shafts, the said shaftshaving .a depending 'circumferentially grooved'portion and a furtherdependin'g'pin like portioneccentric to the circular groove-portion, oneside of-which is coextensive with the face of the circulargrooved'zportionproviding a construction that upon the turning of theshafts through an arc of 130 degrees the pin like por--v tions arespaced the least distance apart, a spring having eyes insertable overthe, pin, like portions of the shafts in opposite directions increasingthe distance between the pins thereby placing a tension upon the spring,said pin like portions providing guide'means for placing the said eyeportions of the springs in their respective grooves of the shafts.

. 11. The combination with, a

panding type providing oppositely disposed end portions, said endportions, said end portions having oppositely inclined beveled" edgestoward the outer face of the band, of an expanding cam, a rotatablewheel in face engagement therewith, the cam and wheel being 50-supported relative to the band thatrotation of the cam in one directioncauses an expansion of the band,

a spring tending to contract the band, and a' pivotally supportedspreader member having oppositelyinclined faces positioned between theinclined faces of. the band ends .whereby upon.

rotatable, brakedrum anda brake band therefor of the split ex-.

-mechanism for the band comprising a rotatable contraction of the bandthe said ends are forced inwardly away from the drum by reasonof contactwith the spreader member. 12. The combination with a rotatable brak drumand a brake band therefor of the split expanding type, of an'expandingmechanism for the band comprising a rotatable cam member,

a rotatable wheel inlface contact therewith, a

shaft for each of'the said cam and wheel members each supported at itsupper end bythe respective ends of the band, a bracket for the lower endof each shaft detachably connected with the brake band adjacent itsopposite ends, a spring extending between the said shafts tendingto'decrease the distance therebetween, a pulley to which the cam isattached, and a cable for rotating the pulley and cam in a directionltoincrease the distance between the axes of the said shafts, said shaftsbeing mounted in parallel relation on an axis at a right angle to theaxis of rotation of the drum. g

13. The combination with a rotatable brake drum and-,abrake bandtherefor of the split expanding type, a cover plate for the drum, anexpanding mechanism for the band housed within the drum and comprising arotatable cammemin parallel relation and at a right angle to the axis ofrotation of the drum, apulley for the cam member, a cable for the pulleyextending tangentially thereto through the cover portion for the drum,said cover portion including an apertured plate through which the cableextends, an 7 35 expanding spring attached at its inner end to theapertured member and at its outer end to the cable, said parts being soarranged that, upon pulling of the cable, the pulley and cam are rotatedcausing an increase in the distance apart of the axes of rotation of thecam and wheel and upon release of pressure the spring, takes up theslack of the cable, and a contracting spring exerting pressure betweenthe wheel and the cam to cause reverserotation thereof upon release ofthe cable and consequent contraction oftheband. 14. In combination'witha brake drum, an expandible band therefor, of an expanding mechanismincludinga rotatable cam, a pulley attachedv thereto and rotatable onthe same axis, a flexible element-for the pulley, said pulley having aradial. aperture opening from 'the rim of the pulley on the one end, atransverse aperture adjacent the rim into which the first named apertureopens at its opposite end, said cam having a aperture formed of two halfparts and providing a conicalrecess in-the outer side of the cam and 100opening at the bottom to the transverse aperture of the pulley, saidtension element having its inner end extending through the apertures ofthe pulleys into the conical recess of the bushing and end.

JOY S. REYNOLDS.

provided with a conical end portion fitting the 05 conical recess of thebushing, the whole providring a quick releasable attachment for thecable

